This question was previously asked in

DSSSB Physical Education General Section - 2 Aug 2021

Option 1 : 0

**Given:**

The cost price of each spectacle = 3000

**Formula used:**

P = SP - CP

L = CP - SP (Where, P = Profit, L = Loss, SP = Selling price, and CP = Cost price)

**Calculation:**

Let be assume profit is P and loss is L

⇒ The profit on first spectacles = 3000 × {(100 + 40)/100} - (3000) = 4200 - 3000 = 1200

⇒ The loss on the second spectacles = 3000 - 3000 × {(100 - 20)/100} = 3000 - 2400 = 600

⇒ The loss on the third spectacles = 3000 - 3000 × {(100 - 20)/100} = 3000 - 2400 = 600

⇒ Total profit = Profit on first spectacles - Loss on second spectacles - Loss on third spectacles

⇒ Total profit = 1200 - 600 - 600 = 1200 - 1200 = 0

**∴ The required result will be 0.**

**Shortcut method:**

There is cost price is the same for each spectacle then,

Total profit = Profit% on first spectacles - Loss% on second spectacles - Loss% on third spectacles

Total profit = 40 - 20 - 20 = 40 - 40 = 0

**∴ The required result will be 0.**